Concrete stud group and construction method thereof
By setting bifurcated legs on the studs to form a three-dimensional spatial anchoring network, the problem of easy debonding of traditional studs under dynamic loads is solved, achieving efficient concrete anchoring and crack delay effects, and improving pull-out resistance and load-bearing capacity.
Patent Information
- Application Number
- CN202511248935.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-03
- Publication Date
- 2025-11-18
AI Technical Summary
Traditional studs are prone to debonding from concrete under dynamic loads, resulting in significant anchorage degradation. Furthermore, under fatigue cyclic loading, the amount of interfacial slippage increases, the interlocking force decreases significantly, and the anchorage stiffness decreases.
The system employs side-by-side studs, each with a forked leg, forming a three-dimensional spatial anchoring network. The forked arms of adjacent studs interlock in the concrete, creating a three-dimensional grid structure that enhances mechanical interlocking force and forms a multi-dimensional constraint system.
It significantly improves the compatibility of concrete, delays crack development, decomposes concentrated loads into multi-level dispersed stress waves, inhibits the penetration of main cracks, improves pull-out resistance and flexural/shear bearing capacity, and achieves synergistic effects under high-density anchorage.
Smart Images
Figure CN120968104A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of concrete construction, in particular to a concrete dowel group and a construction method thereof. BACKGROUND
[0002] Dowels are very common and important anchoring connectors in the field of engineering, especially in concrete building structures and bridge engineering, and can also be used as cast-in-place anchors. The core function of the dowel is to firmly connect the steel structure member (such as a steel beam or a steel plate) and the upper reinforced concrete slab (or a profiled steel slab composite floor slab) together, so that they can work together and bear forces (referred to as a composite structure).
[0003] The anchoring function of the dowel depends on the composite mechanical behavior of the steel-concrete interface: (1) mechanical interlocking force (dominant mechanism): after the dowel rod is wrapped by the concrete, the surface friction and the extrusion of the concrete on the circumference of the dowel form a resistance; (2) uplift bearing capacity: the head of the dowel acts as an "anchoring end" to resist the vertical lifting force of the concrete slab relative to the steel member; (3) bending / shear bearing capacity: when the longitudinal shear force and the bending moment generated at the root of the rod are borne, the anchoring end at the root and the surrounding concrete provide resistance to prevent interface slip and bending deformation; (4) local bearing pressure: the concrete below the head of the dowel bears the compressive stress to avoid local crushing failure of the concrete.
[0004] However, the head of the traditional cylindrical dowel has no texture or opening, and only relies on the end surface pressure. The dowel rod is a smooth cylinder, lacks threads, ribs or barbs to enhance mechanical interlocking, and is easy to debond with the concrete under tension. Moreover, the anchoring of the traditional dowel significantly degrades under dynamic load. After fatigue cyclic loading, the interface slip between the dowel and the concrete increases significantly, and the interlocking force decays significantly. That is, the compression alternating force causes the repeated debonding and resetting of the interface between the concrete and the dowel, and the anchoring stiffness decreases significantly. SUMMARY
[0005] The present application aims to provide a concrete dowel group, which is composed of a plurality of dowel pieces arranged side by side, and the dowel pieces can form a spatial three-dimensional extension of the anchoring network through the setting of a plurality of bifurcated legs with specific angles, establish multiple reverse interlocking nodes in the concrete, change the concrete failure mode from a single conical mode to a spatial network interlocking system, eliminate the risk of stress concentration, and significantly improve the adaptability of low-strength concrete. Another object of the present application is to provide a construction method of a concrete anchor group, which fixes a plurality of anchor members in a pre-buried manner in concrete, forms a three-dimensional grid structure due to the staggered engagement of the diverging arms of adjacent anchor members in the concrete, forms a multi-dimensional constraint system in the concrete, forms a spatial interlocking effect through directional deflection of the diverging structure of adjacent anchors, breaks through the efficiency bottleneck of group anchors under dense arrangement, and realizes synergistic effect under high-density anchoring.
[0006] Embodiments of the present application are implemented as follows: In a first aspect, the embodiments of the present application provide a concrete anchor group, comprising a plurality of anchor members arranged side by side, any anchor member comprising a shank, a base provided at the bottom of the shank, and a diverging unit provided on the shank, and the diverging units of any adjacent anchor members being staggered. In some embodiments of the present application, the diverging unit comprises 4-12 identical diverging legs, the diverging legs being arranged around the shank, and the included angle between any diverging leg and the shank being 45-60°. Further, the number of diverging legs is 8, and the included angle between any diverging leg and the shank is 55°. Further, the bottom of the base is further provided with a heat buffer groove, and the shank, the base and the diverging legs are integrally formed. Further, the diverging legs of any adjacent anchor members cross each other but do not abut.
[0007] In a second aspect, the embodiments of the present application provide a construction method of a concrete anchor group, which uses the above-mentioned anchor member, and comprises the following steps: S1: draw a positioning map, arrange a plurality of anchor member positioning points on a straight line according to the size of the anchor member, the spacing between any adjacent positioning points being the same, and ensuring that the diverging units can be staggered with each other; S2: design a pre-buried support according to the positioning map of step S1, and open positioning holes in the pre-buried support according to the positioning points; S3: fix the pre-buried support at the construction site, then pass the anchor member through the positioning hole, and fix it on the pre-buried support through a bolt connection; S4: pour concrete on the pre-buried support, and remove the pre-buried support after pouring is completed.
[0008] Further, in step S1, the spacing between any adjacent positioning points is greater than twice the diameter of the anchor member and less than four times the diameter.
[0009] Further, in step S3, during the fixing process, a level is used to ensure that all anchor members are at the same height.
[0010] Further, in step S4, the pouring process adopts chute guide to pour, after the concrete slurry covers the bifurcated legs of the bolted piece, the pouring is stopped, and the bolted piece is corrected.
[0011] Further, in step S4, the pouring process adopts chute guide to pour, after the concrete slurry covers the bifurcated legs of the bolted piece, the pouring is stopped, and the bolted piece is corrected.
[0012] Compared with the prior art, the embodiments of the present application have at least the following advantages or beneficial effects: 1. The present application adds a bifurcated unit to the traditional bolt, and designs the included angle between the bifurcated legs and the bolt body to be 45-60°, which can generate normal extrusion force on the vertical crack surface when the crack extends, delay the initial crack and crack development, force the crack expansion direction to deflect, convert the original one-way main crack, even the through crack (splitting) damage into a multi-directional micro-crack energy dissipation mode, and then induce the formation of a spatial network of micro-cracks in the concrete, decompose the concentrated load into multi-level dispersed stress waves, and effectively delay and disperse the main crack penetration trend, thereby inhibiting the formation of a complete classical damage cone. 2. The present application fixes a plurality of bolted pieces in the concrete in a pre-buried manner, and the bifurcated arms of adjacent bolted pieces interlock in the concrete to form a three-dimensional grid structure, forming a multi-dimensional constraint system in the concrete. The bifurcated structure of adjacent bolts forms a spatial interlocking effect through directional deflection, breaks through the efficiency bottleneck of densely arranged group bolts, and realizes synergistic effect under high-density anchoring. BRIEF DESCRIPTION OF DRAWINGS
[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.
[0014] Figure 1 The figure is a structural schematic diagram of the bolted piece in the embodiments of the present application. Figure 2 The figure is a schematic diagram of the bolted pieces cooperating with each other in the embodiments of the present application. Figure 3 The figure is a schematic diagram of the bolted group inhibiting crack extension in the embodiments of the present application.
[0015] Figure legend: 1-bolt body; 2-base; 3-bifurcated leg; 4-threaded segment. DETAILED DESCRIPTION
[0016] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings of the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.
[0017] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.
[0018] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0019] Embodiment 1 Please refer to Figure 1 The embodiment provides a concrete dowel assembly, which comprises a plurality of parallel arranged dowel members, any dowel member comprises a dowel body 11, a base 22 arranged at the bottom of the dowel body 11 and a bifurcated unit arranged on the dowel body 1, and the bifurcated units of any adjacent dowel members are staggered. Further, in the embodiment, the dowel body 1 is in a cylindrical shape, which bears the main axial tension or pressure and transmits the load to the anchoring part, the length of the dowel body 1 determines the effective embedding depth of the dowel member between the connecting member (such as a steel beam) and the concrete, and the upper half of the dowel body 1 is further provided with a threaded segment 4, the length of the threaded segment 4 is not more than one third of the length of the dowel body 1. The base 2 is in a disc shape, which can provide a stable starting point for the bifurcated unit, uniformly distribute the load transmitted by the dowel body 1 to the bifurcated unit, reduce the stress concentration, and at the same time, the disc itself also forms a larger horizontal resistance surface, increasing the difficulty of direct pulling out. The bifurcated unit is arranged at one end of the dowel body 1 close to the base 2, which comprises 4-12 bifurcated legs 3 which are completely same in shape, material and length, all the bifurcated legs 3 are arranged around the dowel body 1, the included angle between any bifurcated leg 3 and the dowel body 1 is the same, which is 45-60°; and the starting points of all the bifurcated legs 3 are on the same horizontal plane, and the spacing between any adjacent bifurcated legs 3 is completely same.
[0020] It is further noted that when the stud is subjected to external force, the initial crack of the concrete starts from the base 2 and gradually develops to the surface of the concrete base material. Its form is usually a radial crack diverging outward from the base 2 of the stud, and the crack develops from a fine crack to a coarse crack capable of forming a failure cone, according to the European standard ETAG 001, the cone crack usually extends at an angle of 35-45° (35° is simulated uniformly).
[0021] In the present embodiment, a plurality of branched legs 3 are arranged around the stud body 1 in a diverging topology. The multi-directionality of the branched legs 3 ensures that the stud member can provide effective anchoring force when subjected to loads in different directions. Moreover, due to the presence of the plurality of branched legs 3, the frictional contact area between the stud member and the concrete is greatly increased, and after the concrete is cured, the entire stud member is better fixed in the concrete matrix, greatly improving the pullout resistance of the stud member.
[0022] Further, the included angle between the branched leg 3 and the stud body 1 is set to 45-60°, which is perpendicular to the extension direction of the crack (or has a certain angle deviation, with a difference of ±10°). This key angle design builds a crack-crossing constraint mechanism in the concrete, which is specifically manifested as follows: when the crack tries to naturally extend along the 35° angle, the branched leg 3 with an angle of 45-60° generates a normal extrusion force perpendicular to the crack surface, forcing the crack to deflect, which will bypass the branched leg 3 or split the path. In this case, a single main crack will be decomposed into a large number of micro-cracks, forming a micro-crack network. The crack dispersion effect formed by this can significantly consume the expansion energy, thereby greatly delaying the progress of failure.
[0023] Among them, the geometric parameters of the stud member (such as rod length, rod diameter and the number of branched legs 3) can be adaptively adjusted according to the performance grade of the concrete and the load spectrum characteristics. For cases where the load requirements are complex or the space is limited, 4-6 branched legs 3 can be selected; while for concrete environments with higher bearing capacity requirements or requiring more uniform stress distribution, the number of branched legs 3 is greater than 8.
[0024] In addition, under the constraint of the same anchoring depth, the increase in the number of stud members can significantly optimize the load transfer path, i.e. induce the formation of a spatial network of micro-cracks in the concrete, effectively delay and disperse the main crack penetration trend, thereby inhibiting the complete formation of the classical failure cone.
[0025] As a preferred embodiment, the number of the bifurcated legs 3 is 8, and the included angle between any bifurcated leg 3 and the body 1 is 55°; such a design can not only ensure that the intersection gap between the bifurcated legs 3 of adjacent bolt members is not too small, but also maximize the angle between the bifurcated legs 3 and the fissure, thereby better promoting the decomposition of the fissure and forming a spatial network of micro-fissures, thereby greatly delaying the progress of the damage.
[0026] Further, the bottom of the base 2 is also provided with a heat buffer groove, which can be a U-shaped groove with a semicircular cross section, or a square groove with a rectangular cross section, or a V-shaped groove with a V-shaped cross section, or a composite groove with a U-shaped bottom and a V-shaped top, which can reduce the thermal stress concentration under welding or high temperature conditions and effectively solve the hidden danger of the heat affected zone during welding. The body 1, the base 2 and the bifurcated legs 3 are integrally formed; the integral forming process ensures the precision of the entire bolt member structure.
[0027] Further, the bifurcated legs 3 of any adjacent bolt members intersect with each other but do not abut. Specifically, the adjacent bifurcated legs 3 are staggered and engaged, but maintain a certain distance, which promotes the formation of a spatial network of micro-fissures to a greater extent, so that the damage surface of the concrete presents a non-continuous honeycomb shape rather than a traditional inverted cone shape. In addition, the cooperation between multiple bolt members forms a three-dimensional grid structure in the concrete, which uniformly disperses the stress borne by the bolt members. It can break through the critical limit of group anchor efficiency under the condition of traditional dense bolt arrangement (i.e. the key mechanical phenomenon that the single bolt bearing capacity and stiffness are reduced due to stress superposition when multiple bolt members are densely arranged).
[0028] Embodiment 2 The embodiment of the present application provides a construction method of a concrete bolt group, which adopts the bolt member of embodiment 1, and comprises the following steps: S1: draw a positioning map, set a plurality of bolt positioning points on a straight line according to the size of the bolt member, and design a group of bolt groups. Wherein, the distance between any adjacent positioning points is the same, and the distance is greater than twice the diameter of the bolt member and less than four times the stable radius; then design a plurality of the same bolt groups according to the requirements of the construction site, and the distance between adjacent bolt groups is the same.
[0029] S2: according to the positioning map of step S1, design a pre-embedded support with corresponding size, and according to the number and position of the positioning points, set corresponding number and position of positioning holes on the pre-embedded support, and each positioning hole is provided with a thread for cooperating with the fixed bolt member. After the design is completed, measure and lay the line.
[0030] The embedded support is selected from channel steel / angle steel, the tensile strength is ensured to be greater than or equal to 500 MPa, and the support rigidity displacement is less than or equal to 1 mm, so that the deformation of the support in the concrete pouring process is avoided, and then the position of the bolt nail part is affected.
[0031] S3: The embedded support is placed in the construction site, the support leg is welded and fixed with the base steel bar, then a 45° inclined brace is additionally arranged to further fix the support, finally the top surface is leveled by using a level, and the standard height deviation is ensured to be less than or equal to ± 3 mm. After the fixing is completed, the bolt nail part is passed through the positioning hole and fixed on the embedded support by using a bolt; during the fixing process, the position of the bifurcated leg 3 is adjusted, the bifurcated legs 3 of adjacent bolt nail parts are ensured to be staggered with each other but not to be in contact with each other, and after the fixing is completed, the calibration is performed by using a level, and all the bolt nail parts are ensured to be at the same horizontal height.
[0032] S4: The embedded support is poured with concrete, the pouring process is performed by using a chute guide to pour layer by layer, each layer is poured to be less than or equal to 500 mm, and during the pouring process, it is noted that the concrete is not directly impacted on the bolt nail part; after the concrete liquid completely submerges the bifurcated leg 3 of the bolt nail part, the pouring is stopped, and the concrete is solidified. During the solidification process, the bolt nail part is corrected by using a jack, and after the concrete is preliminarily hardened for 24 hours, the embedded support can be removed.
[0033] In summary, the embodiment of the present application provides a device and a method, by additionally arranging the bifurcated unit on the basis of the traditional bolt nail, and designing the included angle between the bifurcated leg 3 and the bolt body 1 to be 45-60°, the normal extrusion force perpendicular to the crack surface can be generated when the crack extends, the crack expansion direction is forced to deflect, the original one-way splitting damage is converted into a multi-directional micro-crack energy dissipation mode, and then the space network micro-crack distribution is induced in the concrete, the concentrated load is decomposed into multi-stage dispersed stress waves, the development of the concrete crack is degraded from the through main crack to the dispersed micro-crack network, the complete formation of the classical damage cone is effectively delayed and dispersed, and the complete formation of the classical damage cone is effectively delayed and dispersed. By fixing the plurality of bolt nail parts in the concrete in a pre-embedded manner, the bifurcated arms of adjacent bolt nail parts are staggered and engaged in the concrete, a three-dimensional net rack structure is formed, a multi-dimensional constraint system is formed in the concrete, the bifurcated structure of adjacent bolt nails forms a space interlocking effect through directional deflection, the group nail efficiency bottleneck under the dense arrangement is broken through, and the synergistic effect under the high-density anchoring is realized.
[0034] The above is only the preferred embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A concrete stud assembly, characterized in that, It includes several studs arranged side by side, each stud comprising a stud body, a base at the bottom of the stud body, and a bifurcated unit on the stud body, wherein the bifurcated units of any adjacent studs are staggered.
2. The concrete stud assembly according to claim 1, characterized in that, The bifurcation unit includes 4-12 identical bifurcation legs, which are arranged around the plug body, and the included angle between any bifurcation leg and the plug body is 45-60°.
3. A concrete stud assembly according to claim 2, characterized in that, The number of the forked legs is 8, and the included angle between any of the forked legs and the plug body is 55°.
4. A concrete stud assembly according to claim 3, characterized in that, The base is also provided with a heat buffer groove at the bottom, and the bolt, the base and the forked leg are integrally formed.
5. A concrete stud assembly according to claim 4, characterized in that, The forked legs of any adjacent stud member cross each other but do not abut against each other.
6. A construction method for a concrete shear stud assembly, employing a shear stud component as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Draw a positioning diagram. Based on the dimensions of the stud, set several stud positioning points on a straight line. The spacing between any adjacent positioning points is the same, and ensure that the bifurcated units can intersect each other. S2: Based on the positioning diagram described in step S1, design a pre-embedded bracket and open positioning holes on the pre-embedded bracket according to the positioning points. S3: Fix the pre-embedded bracket to the construction site, then pass the stud through the positioning hole and fix it to the pre-embedded bracket by bolt connection; S4: Pour concrete into the embedded support, and remove the embedded support 24 hours after the pouring is completed.
7. A construction method for a concrete stud assembly according to claim 6, characterized in that, In step S1, the distance between any adjacent positioning points is greater than twice the diameter of the stud and less than four times the stabilizing radius.
8. A construction method for a concrete stud assembly according to claim 7, characterized in that, In step S3, during the fixing process, a level is used to ensure that all the studs are at the same horizontal height.
9. A construction method for a concrete stud assembly according to claim 8, characterized in that, In step S4, the pouring process is carried out by using a chute for diversion. After the concrete liquid submerges the bifurcated leg of the stud, the pouring is stopped, and the stud is corrected for deviation.
10. A construction method for a concrete stud assembly according to claim 9, characterized in that, Step S4 also includes removing the embedded support after the concrete has initially hardened for 24 hours.